Lubricant compositions containing polychloroalkyl benzene extreme pressure additives



United States Patent Ofihce 3,3721 19 Patented Mar. 5, 1 968 4 Claims.ci. 2sz-4s.s

ABSTRACT OF THE DISCLOSURE A lubricant additive for use at extremepressures comprising a mixture of a chlorinated alkyl benzene having achlorine content of from 50 to 75% by weight, at least 75 of which isbound to the alkyl carbon atoms, and a resinous polychlorobenzenepolysulfide soluble in hydrocarbon oils and containing from 15 to 25%sulfur and from 44 to 55% chlorine.

The present invention relates to new additives for lubricants and inparticular to products capable of imparting extreme pressure propertiesto lubricating oils, making them more suitable for use as cutting oils.It is also concerned with a process for the preparation of these newproducts.

It is the usual practice to incorporate various adjuvants intolubricants, the purpose of which is to improve the lubricating power,inhibit corrosion, serve as dispersion agents or viscosity-modifyingagents, etc. In the very important case of cutting oils, which generallyWork under very severe conditions of use, it is imperative to employjudiciously selected additives. Actually, when it is subjected to thevery high pressures developed on the cutting edge of the tool thelubricating film formed by a normal oil has a tendency to be broken up,thus removing the lubrication at the point where normally it should beapplied. The addition of an additive serves the purpose in this case ofcausing the formation of a second lubricating film which is moreresistant than the first, simultaneously on the cutting edge of the tooland on the element in contact with the latter.

A large number of extreme pressure additives have already been proposedand the majority of these are chlorinated derivatives, sulphur orphosphorus derivatives, alone or in combination. Among the chlorinatedcompounds most employed at the present time, there may be mentioned thechlorinated diphenyls or polyphenyls and particularly the chlorinatedparaflins.

It has also been proposed to use chloralkyl benzenes, as for example the30.5% chlorinated dodecylbenzene, obtained in the form of a reddishbrown opaque oil by chlorination of the hydrocarbon in the presence ofultraviolet rays at increasing temperatures which vary between 100 and220 C.

The new additives according to the invention have an efiiciency which isdistinctly better than that of the already known chlorinatedderivatives, that is to say, the rates of wear of the metal elementworking under high pressures are comparatively much lower and, inaddition, the seizing phenomena of the element or tool only occur atvery strong pressures which are higher than those corresponding forexample, to the chlorinated paraflins. In addition, in view of theirvery high chlorine content, these additives can be used in very smallquantities and, in any case, for identical rates of wear and seizingpressures, certainly smaller than those of the prior known chloralkylbenzenes.

These additives according to the present invention are formed byaromatic hydrocarbons substituted by one or more chlorinated alkylradicals, at least one of these radicals containing a minimum of 5carbon atoms, the total chlorine content in the said hydrocarbons beinggreater than 50% The long-chain alkyl radical may comprise 5 to 30carbon atoms, it being possible for the aliphatic chain to be linear orbranched. The aralkyl hydrocarbons chlorinated by substitution on theside chains and comprising several medium or long chain alkyl radicalson the arcmatic nucleus, as well as mixtures of aralkyl hydrocarbonscomprising at the same time lower alkyl radicals and at least one alkylradical with more than 5 carbon atoms, also come within the scope of theinvention.

The precentages of chlorine fixed onthe aliphatic radical may varybetween wide limits and the additives according to the invention maycontain in total 50 to of chlorine. The chlorination process accordingto the invention consists in introducing a current of chlorine into thehydrocarbon or mixture of aromatic alkyl hydrocarbons kept in the darkat a temperature between 40 and 180 C.

The reaction, which is prefer-ably effected in the absence of a solvent,does not generally require the use of a catalyst. Nevertheless,according to a modification of the process according to the invention,it is possible to employ small quantities, for example, 2 to 8% byweight of the batch, of a catalyst which promotes the chlorination ofthe aralkyl hydrocarbon on the side chain or chains. This catalyst maybe formed, for example, by a phosphorus polyhalide, such as phosphorustrichloride. Under these conditions, the reaction temperature can belowered appreciably and it is then generally between 40 and C.

As initial aralkyl hydrocarbons, it is for example possible to usebenzene hydrocarbons substituted by a longchain alkyl radical, such as:pentyl, hexyl, octyl, nonyl, decyl, dodecyl, tridecyl, tetradecyl, etc.The alkyl radical may in addition be branched, it being possible for oneor several hydrogens of the carbon atoms in the linear chain to besubstituted by alkyl radicals, such as: methyl, ethyl, propyl, etc. Thefollowing may be mentioned as examples of branched alkyl radicals:2-methyl pentyl, 2,3-dimethyl pentyl, 2-methyl-4-propyl pentyl, 2-ethylhexyl, 4,6-dimethyl nonyl, etc. Additives which are likewiseadvantageous are formed by chlorination products of alkylates ormixtures of heavy alkylates, obtained at the time of distillation ofalkylation products of benzene with branched or unbranched olefins (asfor example the tetramer of propylene). As examples, there may bementioned the alkyl or polyalkyl benzenes known under the registeredtrademarks: Progiline 152, Solgil 54, Solgil 109, Solgil 110, Alkylat1163, etc. As stated above, it is also possible to employ mixtures ofthese products, in which the length of the alkyl chain varies between 5and 30 carbon atoms.

The reaction generally takes place under atmospheric pressure butobviously it is possible to work under higher or lower pressures. It maybe conducted continuously or intermittently and it is possible todetermine the proportion of fixed chlorine by the usual methods, as forexample the measurement of the variations in physical characteristics,such as density, refractive index, etc.

The chlorinated products obtained according to the invention are in theform of more or less viscous liquids or solids, which are generallycolorless or with a slight yellowish orange coloration. The totalproportion of chlorine therein is preferably between 52 and 60% for thepurposes according to the invention.

Although the new additives according to the invention are veryefficient, one modification of the invention enables their action to befurther strengthened. According to this modification, the effect of thepolychloroalkyl aryl compounds on the lubrication is increased in asurprising fashion by the addition of resinous polyhaloarylpolysulphides, which are in themselves agents for improving lubricatingoils, but to a lesser degree than when they are employed in conjunctionwith the polychloralkyl aryl compounds.

Thus, when one of the polychloralkyl aryl compounds described above ismixed with a resinous polychloraryl polysulphide which is soluble in thehydrocarbons and which is referred to in French Patent No. 1,339,529 orNo. 1,335,514, it is unexpectedly found that the mixed additive which isformed is more active than is the case with each of its constituents,taken separately. The haloaryl polysulphide employed most usuallycontains, by weight, 15 to 25% of sulphur and 44 to 55% of chlorine.

The mixed additive in accordance with the modification of the inventionmay contain variable proportions of each of its constituents, forexample, to 90 parts by weight of polychloralkyl aryl compound to,respectively, 90 to 10 parts of resinous haloaryl polysulphide.

The content of this mixed additive in the lubricants may advantageouslybe from 2 to 10% by weight.

Although certain chlorinated additives according to the invention arerelatively stable over a period of time at normal temperature, othersare decomposed more or less quickly from 30 to 40 0, thereby liberatinghydrochloric acid. It is possible considerably to limit this degradationby the chlorinated product having incorporated therein one or more heatstabilizers and/ or light stabilizers of known types. By way ofnon-limiting example, the additives may have added thereto: metal saltsof fatty acids, such as barium or cadmium laurates and stearates,organo-tin derivatives, epoxidized agents, hydroxybenzophenones,derivatives of alkylene oxide, sulphonamides, morpholines, etc.

Among the stabilizers capable of producing a good stabilization of thechlorinated additives according to the invention up to temperatures of150 C. and higher, there are to be considered, for example, epoxidizedcompounds, such as epoxidized soya oil, used at the rate of 1 to 10% ofthe weight of chlorinated hydrocarbon, alone or admixed with 0.5 to 4%of a hydroxybenzophenone, such as 2-hydroxy-4-methoxybenzophenone.

Furthermore, for improving the resistance to corrosion in the presenceof the chlorinated additives, it is sometimes advantageous toincorporate small quantities of corrosion inhibitors of known type, asfor example amines or polyamines, mercaptans, alkali compounds, capableof neutralizing the decomposition products which could be formed withthe use of the cutting oil.

The quantity of chlorinated additive to be incorporated into a lubricantfor permitting it to be used as a cutting oil at extreme pressure isobviously a function of the nature of this lubricant and of the work forwhich it is intended to be used. This quantity may vary generallybetween fairly wide limits, for example between 0.2 and 20% of theweight of lubricant. In the case of cutting oils for high pressure, thedesirable quantities are frequently between 2 and 10% by weight. It isgenerally advantageous to use a proportion of additive such that thechlorine content in the lubricating composition is of the order of 1.5to 4%. It is then found that there is a very great increase in thebinding limit and also a considerable reduction in the wear of the tool.

The lubricating oils containing the additives according to the inventionmay be used for numerous purposes, as for example hypoid drives, motors,cutting of metals, lubrication of drilling bits and rod sections whensinking petroleum wells, etc.

The following examples, given in non-limiting manner, show how theinvention can be carried into effect. Examples 1 to 6 illustrate thepreparation of a certain number of aralkyl hydrocarbons chlorinated tomore than 50% in accordance with the invention. Examples 7 to 14illustrate the good results obtained when using these chlorinatedproducts as extreme-pressure additives, and also their superiority ascompared with previously known chlorinated additives.

The tests of the additives to cutting oils were carried out with the4-ball Shell machine, particularly described in the journal Engineeringof July 13, 1933, vol. 136, page 46. The values indicated in the tablesfor establishing the wear represent the mean of three similar tests.

Unless otherwise indicated, all the percentages are in parts by weight.

Example 1 Employed as initial hydrocarbon is a cut of alkylationproducts of benzene, boiling between 160 and 210 C. and containing amixture of alkyl benzenes of the mean empirical formula C H C H 410 g.of the aforementioned hydrocarbon are introduced into a two-litrespherical flask kept in the dark and equipped with a stirrer device, acondenser, a gas supply tube and a heating system. Then, after havingheated the flask to about C., a stream of chlorine is caused to bubbletherein at an average rate of 24 l./hr.

After chlorination for 30 hours at temperatures between 120 and 0,followed by nitrogen degasification of the flask, there are obtained 880g. of a viscous light yellow liquid with a chlorine content of 55.6%.

Analyses of the product, carried out on the spectra of nuclear magneticresonance and also the infra-red and ultra-violet spectra, made itpossible to establish that the chlorination had been effected for themajor part (that is to say, to more than 75% of the consumed chlorine)on the alkyl chain of the initial hydrocarbon. The chlorinated producthad the characteristics: d 1.460; n =1.5805.

Example 2 The same equipment and the same initial material as in Example1 were employed. Starting with 842 g. of hydrocarbon, the chlorinationwas effected in the dark for 30 hours, keeping the temperature betweenand C. The rate of flow of chlorine was regulated to a value of about 60l./hr. for 10 hours, then 48 1./hr. for the following 10 hours, andfinally 24 l./hr. during the last 10 hours. After degasifying the flaskwith nitrogen, there were obtained 1873 g. of an alkyl benzenechlorinated mainly on the chain and in the form of an orange-yellowviscous liquid with a chlorine content of 57.2%. Refractive index: n=1.59l4. Density=d =1.495.

Example 3 The operation was carried out with the same equipment and thesame initial hydrocarbon as in Example 1, but starting with 274 g. ofproduct, to which had been added 13.7 g. (i.e. 5% by weight) of PCl Bymaintaining a chlorine rate of 24 l./hr. for 55 hours and at 50 C.(always in the dark), there were obtained 560 g. of a viscous colorlessliquid with a chlorine content of 52.8%. Characteristics: (1 :1415. n=1.574.

Example 4 The same initial materials as in Example 3 were used, but withthe following proportions and under the following conditions:

Weight of hydrocarbon 322 g.

Weight of PCI 10g. (3% by weight).

Rate of flow of chlorine 36 l./hr. for 12 hours, then 24 l./hr. for 12hours.

Temperature 90 to 100 C.

After degasifying the reaction mass with a stream of 5 nitrogen at 95 C.for 1% hours, there were obtained 665 g. of a colorless viscous liquidwith a chlorine content of 54.2%. Characteristics: n =1.578; d ==1.440.

Example 5 The operation was carried out as indicated in Example 1, usingas starting material an alkyl benzene fraction boiling between 160 and240 C., in which the number of carbon atoms of the alkyl chains variedbetween 5 and 11. By chlorinating in the dark with a rate of flow ofchlorine of 30 l./hr. for 15 hours, and then of 20 l./hr., at atemperature between 115 and 120 C., there was obtained after 37 hours alimpid viscous liquid which was yellowish in color and had a chlorinecontent of 54.7%.

Example 7 For the purpose of studying its extreme-pressurecharacteristics in a lubricant, the product obtained in Example 1 wasdiluted, on the one hand, in a naphthene type oil known as SHELL carnea21 (trademark) and, on the other hand, in a paraffin type oil known as350 Neutral (trademark), which designates a lubricating grease obtainedby distillation of petroleum, and of which the Saybolt viscosity at 37.8C. is 350; the dilution rate was such that the chlorine content in eachof the oils was 2.64% (i.e. about 4.7 g. of adjuvant in 100 g. ofmixture).

The following table shows the rates of wear which were found, as afunction of the pressure, after measurement on the 4-ball machine. Byway of comparison, two other tests were carried out under exactly thesame conditions as above, but with a chlorinated paraffin, used in thesame quantity, in place of the chlorinated additive according to theinvention.

Wear (in mm.)

Pressure Chlorinated alkyl benzene Chlorinated paraffin (in kg.) of theinvention N apthene Paraffin N apthene Paratfin oil oil 011 011 1Seizing at (kilograms).

Example 8 Wear (in mm.) Pressure (in kg.)

Naphthene oil Paraifin oil 1 Seizing'. E I 9 xamp e The operation wascarried out as indicated in Example 7, with the same proportions ofchlorine and the same oils, but using 54.7% chlorinated alkyl benzene asadditive, this being prepared according to Example 6 The resultsobtained were:

Wear (in mm.) Pressure (in kg.)

Comparative tests were carried out on the 4-ball machine by dilution ina naphthene oil, under the same conditions as in Example 1, firstly the55% chlorinated dodecyl benzene of the above Example 5 (product A) andon the other hand the 30% chlorinated dodecyl benzene (product B), whichis already known for its extremepressure properties.

The 30% chlorinated hydrocarbon was used in a proportion clearly higherthan that of the 55 chlorinated product, so as to have, after the samerates of dilution in the oil, equal contents of chlorine (2.50%).

The results as indicated in the following table were obtained:

Wear (in mm.)

Pressure Product A Product B Example 11 The chloralkyl benzene with52.8% of Cl, obtained according to Example 3, added to the paraflinlubricating oil 350 Neutral at respective rates of 4% and 8% by weight,showed the following results as regards wear:

Wear (in mm.) Pressure (in kg.)

Example 12 The present example is given to serve as comparison with themodification of the invention illustrated by Example 13. It concerns aresinous polychlorobenzene polysulphide containing 19% of sulfur and 49%of chlorine, which belongs to the group of additives -for lubricatinggreases described in French Patent No. 1,339,529.

This polysulphide was prepared in the following way: 20 g. of AlCl wereadded to 817 g. of a mixture comprising 30% of trichloro-1,2,3-benzene,65% of trichloro- 1,2,4-benzene and 5% of tetrachloro-1,2,4,5- and-1,2,3,4- benzenes; 405 g. of S Cl previously diluted with 363 g. of thesame trichlorobenzenes and tetrachlorobenzenes as indicated above, areprogressively introduced over a period of 2 hours into the well stirredmixture, brought to 45% C. The total mixture then was kept at 45 C.,while stirring, for half an hour, after which it was heater to 80 C. for2 hours. The product of the reaction was then poured into water; theelimination of the AlCl was obtained by washing with dilute HCl,followed by a washing with a dilute solution of sodium carbonate, thenWashing operations with water until neutral. The organic phase, afterdecantation of the aqueous phase, was subjected to a distillation at mm.Hg until its temperature had reached 195 to 200 C. Thus, 260 g. oftrichlorobenzenes were eliminated and there were recovered 950 g. ofresinous polychlorobenzene polysulphides containing 49% by weight of Cland 19% by weight of S.

This substance was tested as an additive to the 350 Neutral oil underthe same conditions as in Examples 7 to 11; for proportions of additiveof 4% and 8% by weight, there were respectively found:

Wear (in mm.) Pressure (in kg.)

Example 13 Wear (in mm.)

Pressure (in kg.)

1 seizing. Z Seizing above (kilograms).

These results are clearly better than those of each of Examples 11 and12.

Example 14 Tests similar to those of Example 13 were carried out with a/75 composite additive, that is to say, a mixture of 25 parts by weightof the same polychlorobenzene polysulphide with 75 parts of the samepolychloroalkyl benzene as in the preceding example.

The wear values were then:

Wear (in mm.)

Pressure (in kg.)

1 Seizing above (kilograms).

These results, even better than those of Example 13, show that theproportion of 25/75 between the polysulphide and the polychloroalkylbenzene is more favorable than 15/ 85. There is a genuine synergisticeffect between the two constituents, since the mixture thereof has anaction on the lubrication which is clearly superior to that of each ofthe constituents taken separately, as is the case in Examples 11 and 12.

The chlorinated alkyl benzenes used in the examples were stabilizedbeforehand, as indicated in the foregoing description. The thermalstability at 140 C., in the presence of iron and copper, was very goodafter one Week. The resistance to water was excellent and in addition notrace of corrosion was observed with metals such as steels, copper andcast iron. The results of the examples which have been described showthat the additives according to the invention have practically the sameactivity in the naphthene oils and the parafiin oils. These results arealways better than those which are obtained when other chlorinatedadditives of known type are used.

On the other hand, it is apparent that the action of the additivesaccording to the invention can be greatly improved by the addition ofpolysulphides of resinous polychloraryls; the mixed additives formed inthis way have a more favorable effect on the lubrication than that whichis achieved with each of the constituents taken separately.

We claim:

1. A lubricant composition containing, as a principal lubricatingconstituent, a lubricating oil and from 0.2 to 20% by weight of thecomposition of an extreme pressure lubricant additive comprising amixture of from 10 to 90 parts by weight of a chlorinated alkyl benzenehaving a chlorine content of fro-m 50 to by weight, at least 75% of thechlorine content of said additive being bound to alkyl carbon atoms andat least one of the chloroalkyl radicals of the said additive havingfrom 5 to 30 carbon atoms, and from 90 to 10 parts by weight of aresinous polychlorobenzene polysulfide soluble in hydrocarbon oils andcontaining from 15 to 25% sulfur and 44 to 55% chlorine.

2. The lubricant composition as defined in claim 1, which contains from2 to 10% of the extreme pressure lubricant additive, and in which thechlorinated alkyl benzene constituent thereof has a chlorine content offrom 52 to 60% by weight.

3. The lubricant composition as defined in claim 1, in which the extremepressure lubricant additive comprises from 75 to by weight of saidchlorinated alkyl benzene and from 15 to 25% by weight of said resinouspolychlorobenzene polysulfide, and in which the resinouspolychlorobenzene polysulfide is soluble in paraflinic oils and containsabout 15% sulfur and 49% chlorine.

4. The lubricant composition as defined in claim 1, in which thelubricating oil is a naphthenic base oil or a paraffinic base oil.

References Cited UNITED STATES PATENTS 2,121,824 6/1938 Prutton 252582,208,161 7/1940 Prutton et al. 25248.8

3,175,972 3/1965 Mitacek et a1. 2-5248.8 XR

3,179,592 4/1965 Smith et al 25258 FOREIGN PATENTS 1,335,514 6/1963France.

OTHER REFERENCES Hugel Erdol V. Kohle, vol. 8 (1955), pp. 651655 (TN 860E 7).

DANIEL E. WYMAN, Primary Examiner.

W. H. CANNON, Assistant Examiner.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No 3 ,372,119' March 5 1968 Bernard Demoures et a1.

It is certified that error appears in the above identified patent andthat said Letters Patent are hereby corrected as shown below:

In the heading to the printed specification, lines 5 to 7 fo r"BernardDemoures, l4 Quai Jayr, Rhone, Lyon, France and GerardSchneider, 119 Quai Clemenceau, Rhone, Caluire, France" read BernardDemoures, Lyon, France, and Gerard Schneider,

Ca1u1re, France, assignors to Societe Progil, Paris, France Signed andsealed this 22nd day of July 1969.

(SEAL) Attest:

Edward M. Fletcher, Jr.

Attesting Officer Commissioner of Patents WILLIAM E. SCHUYLER, JR.

